No positive yet, but had what I think was implantation?

Hello! So I ovulated 9/9-9/10 (dates not for sure but estimated based on discharge) hubs and I did the deed 9/9, 9/18, 9/20 but he pulled out every time. My period tracker app had me estimates to start AF 10/1 but 9/24 (7 days before expected AF) I had spotting and cramping along with a stuffy nose and sore throat. I tested with three tests this morning and they were all negative. Could I have had Implantation you think and just tested too early? Anyone not get a positive yet but have symptoms like this?